dpends on how you are enabling the control. if you are using a PostbackUrl,
this is done in javascript by setting the button's onclick event to
WebForm_DoPostBackWithOptions. one of the args is the postback url. this
function updates the action, does a form submit and cancels the buttons event.

view source to see what javascript is on the button's onclick (maybe you
defined an action that prevents the proper behavior).

-- bruce (sqlwork.com)

It might be because in the javascript code, you have set the return
statement to false. i.e. return false;
If it is so, the button will not postback